The Healthy Heart—and the Broken One

Bryce J. Christensen and Robert W. Patterson

Marriage protects men and women from fatal heart attacks. Indeed, even among individuals who do suffer a heart attack, men and women are more likely to survive if they are married than if they are not. The relationship between marital status and fatal heart attacks receives illuminating attention in two European studies: one by researchers at the University of Stirling and University College London in Great Britain, and a second by researchers at Skåne University in Sweden. The British study measures the degree of protection from fatal heart attacks enjoyed by married men and women and tries to account for that protection. The Swedish study scrutinizes the distinctively high survival rates among married men and women who do suffer a heart attack.

The British researchers begin their investigation fully aware that married men and women are decidedly less vulnerable to fatal heart attacks than their single, divorced, and widowed peers. But they press their inquiry in the hopes of “understanding why marital status is strongly and robustly associated with subsequent cardiovascular disease.” In pursuit of such understanding, the researchers track the heart health and the survival rates of 13,889 Scottish men and women with an average age of 52 years at the beginning of the study, all without a history of clinically diagnosed cardiovascular disease.

As they expected, the researchers conclude that “all unmarried states were associated with a higher risk of cardiovascular mortality with the exception of widowed women. In general, the risk of death was higher for cardiovascular causes, especially in the case of single or widowed men, and separated/divorced women.” More narrowly, the researchers calculate that single, never-married men were almost three times more likely to die of heart disease than their married peers (Odds Ratio, 2.97). Similarly, the researchers find that single, never-married women were more than twice as likely as their married peers (Odds Ratio, 2.23) to have died of cardiovascular disease during the study period. These findings were not surprising; rather, they were “largely concordant” with studies in the United States and Japan.

In explaining this already well-established pattern, the Stirling and London scholars examine the relationship between marital status and health habits. They find that “all unmarried categories for men and women were significantly more likely to smoke” than were their married peers and that separated, divorced, and widowed men were significantly more likely “to engage in hazardous drinking” than were their married peers. The researchers also document significantly more “psychological distress” among “all unmarried categories of men and women” than was evident among the married comparison groups. Compared to married men, separated and divorced men were also significantly more likely to suffer from hypertension. Single, never-married men and women were more likely to suffer from diabetes.

By entering these data into appropriate statistical models, the British researchers are able to establish that “health behaviours, psychological distress and metabolic dysregulation” accounted for between 16 percent and 39 percent of the gap in cardiovascular mortality separating married individuals from their unmarried peers. This conclusion, while helpful, leaves most of the gap unexplained. Indeed, when the researchers probe more deeply, they find that for single, never married women “direct influences of marriage” may be more important in determining their disadvantage in cardiovascular mortality than are the “indirect processes through health behaviour and psychological distress” that seem to be more important in creating the disadvantage in cardiovascular mortality seen among unmarried men.

If this finding causes readers to marvel yet again at the mysterious denigration of wedlock among radical feminists, such marveling will only intensify when they shift their attention to the Swedish study, which looks at a similar but more narrowly defined research question. Looking specifically at survival rates of men and women who do suffer a heart attack, the Swedish researchers find, yet again, a protective effect of marriage for both men and women.

This protective effect emerges quite clearly when the researchers weigh data collected from 22,347 Swedish men (3,035 of whom had suffered a heart attack), and 10,877 Swedish women (507 had suffered from a heart attack). That is, 14 percent of the men in the study and 5 percent of the women suffered a heart attack during the study period. But the risk was not equally distributed: “Both in men and women,” the researchers note, “this proportion [of individuals suffering a heart attack] was significantly higher in unmarried compared to married cases.”

When the Swedish researchers dig deeper, they find that unmarried individuals are not only more vulnerable to having a heart attack in the first place but are also more likely to die as a consequence. Among men who have suffered a heart attack, the researchers calculate that the survival rate for the first day of the cardiac event runs almost twice as high among married men as it does among divorced and never-married peers (Odds Ratios, 2.14 and 1.91, respectively). The researchers find essentially the same pattern when examining data for 28-day survival rates.

Similarly, among women who have suffered a heart attack, those who are married are decidedly more likely to survive the day of the cardiac event than those who are never-married, divorced, and widowed. True, the marital advantage in survival rates for women suffering from heart attacks does fall below the threshold of statistical significance when the comparison group is never-married women if researchers use models that take into account health habits, pre-disposing biological conditions, and occupational status. In the same way, the marital advantage of 28-day survival rates falls out of the range of statistical significance for women when researchers deploy sophisticated models that account for key background differences. However, the researchers acknowledge that it is “likely that the absence of a significant [statistical] relation in women was explained by limited statistical power.” In other words, the researchers suspect that the only reason that they do not see a statistically significant marital advantage in women’s survival rates in their most sophisticated statistical model is that the study sample of women who suffered a heart attack is too small—far smaller than the sample of men. However, even with this small sample, and even with the most sophisticated statistical adjustments for background variables, the researchers still do discern a statistically significant advantage in 1-day survival rates for married women when the comparison groups are restricted to divorced and widowed women (Odds Ratios, 1.87 and 2.74, respectively).

Regardless of the statistical complexities, the Swedish researchers articulate a clear overall conclusion, one that strongly underscores the results of the related British study on cardiovascular mortality: “Our findings suggest that being unmarried increases the risk of both having a first C[ardiac]E[vent] and dying from the event. As this relationship was independent of many biological- and life-style risk factors, it may reflect a protective effect of marriage.”

As policymakers frame policies affecting health, they ought to take the findings of both of these studies to heart.